1. Field of the Invention
The present invention relates to a camera having a vibration correction function.
2. Related Background Art
Various vibration correcting devices (e.g., Japanese Patent Application Laid-Open No. 5-224270) for cameras have been proposed so as to correct a camera shake, and in particular, the blurring of an image occurring when a camera is inclined. In such vibration correcting devices, an angular speed sensor is utilized as vibration detecting means for detecting a camera shake and vibrations. The angular speed sensor detects the angular speed of the camera shake. In accordance with the result of the detection, vibration correcting means is driven to shift a taking lens system as a principal optical system or a vibration correcting optical system as a portion of the taking lens system in a direction perpendicular to the optical axis to correct the blurring of an image.
Therefore, in cameras equipped with such vibration correcting devices, even though exposure is carried out at a slower shutter speed than that in the ordinary photographing, it is possible to take a photograph with no blurring.
A vibration detecting circuit of the vibration correcting device is stopped by cutting off a power source supplied to the vibration detecting circuit.
In this case, each time one frame of a photographic film is exposed, the vibration detecting circuit is stopped. However, when the vibration detecting circuit is once stopped (the power source is cut off), it takes time for the vibration detecting circuit to be stabilized again after the redriving thereof (resupply of the power source). Therefore, in the case of a camera with a continuous shot photographing mode, even at the time of a continuous shot photographing, the vibration detecting circuit is stopped and redriven for each shot. Accordingly, intervals of photographing need to be lengthened. As a result, the continuous shot photographing cannot be carried out speedily.
Also, conventionally, vibration correction is performed for each frame. However, at the time of the continuous shot photographing, it is necessary to make wait time between frames as short as possible, which causes a problem. Namely, in the continuous shot photographing, there is a case where a photographer takes photographs while changing the composition, so that the camera might be moved largely between frames. When a vibration reference signal level (.omega.=0) is detected during the wait time between the frames and the continuous photographing is carried out while changing the composition, the amount of camera shake cannot be detected properly; on the contrary, an abnormal correcting operation is carried out. As a result, image quality is deteriorated considerably.
Also, the technique on the autofocus detection of a taking lens of a camera is known. When abnormality occurs in the autofocus detection, if a vibration correcting function is kept operating even though the abnormality is detected, a battery is spent in vain for the vibration correction.
Further, in conventional cameras with a vibration correction function, generally, a vibration detecting device for detecting an amount of vibration and a vibration correcting device for correcting the vibration are kept operating while a power source of the camera is switched on. However, there is a problem that during moving a refractive power operation of a variable power lens, accuracy of the vibration detection is lowered due to vibration of the variable power lens and noise of a drive motor, or a voltage drop caused by the drive of the motor.